Field of activity

Fundamental properties and processes of simple atomic and molecular
systems are being investigated both experimentally and theoretically.
At present, the main emphasis is on the investigation of
laser-assisted collisions.

In consequence of the emeritation of Prof. B. Brehm the
section has become smaller and concentrates their activities
on a smaller field.

Current work is focused on the following topics:

Laser-excitation of collision pairs (Optical Collision)

Experimental methods have been developed, which allow the direct
observation of atomic or molecular collisions and the coherent control
of elementar collision processes. We have already
been able to make geometric observations of a collision complex
("photograph" of a collision). This is a remarkable success,
because the object, which we observe, is both small
(10-10m) and short lived (10-12s).
With this method, sensitive tests of molecular potentials have
been performed and nonadiabtic transitions have been analysed.
It has been shown, that time resolved experiments of this type with
femtosecond lasers can be done, too ("movie" of a collision).

The inelastic cross-sections of atom-atom collisions at low energies
play an important role for the calculation of non-equilibrium phenomena
in diluted gases, e. g. atmospheres of stars or Laser plasmas.
The inelastic cross-sections are obtained from completely
quantummechanical ab-initio calculations. The results can be interpreted
conspicuously.